Author

Echocardiography is often an essential component in the management
of a critically ill patient and setting up a service of acceptable quality
requires attention to efficiency, sustainability and operator competency.

Introduction

The value of echocardiography at the bedside of a critically ill
patient is well established (Cholley et al. 2006). Initially provided as an
offshoot of regular radiology or cardiology ultrasound services,
echocardiography in the care of the critically ill patient has increasingly
been performed by critical care physicians themselves (Kaplan and Mayo, 2009).
In addition to the obvious diagnostic advantages, real time echocardiography allows
a greater focus on haemodynamic evaluation, thereby providing essential patient
information in a more timely fashion. However, this enhancement to patient care
comes with responsibilities, often unappreciated when contemplating setting up
or expanding an already existent rudimentary service. Good planning will save
frustration and costs compared with allowing development to occur in an ad hoc
fashion.

Components to be considered include machine selection, recording
and reporting studies, archiving, interdepartmental connectivity and training.
Machine availability, a major challenge in the past, is less so now with less
expensive, yet more sophisticated machines, within the budget of many Intensive
Care Units (ICUs). It is acknowledged that machine acquisition may still be a problem
in developing countries, especially where external influences dictate who may
or may not have ready access to machines on site. Often overlooked when setting
up an in-house service are machine care, maintenance costs, producing quality
images in wellstructured examinations, recording images, archiving images and
delivering reports that can be accessed in other sections of a major hospital.

Training remains a major challenge, not only in the availability
of adequate educational resources, where the emphasis on practical hands-on
training predominates at least for beginners, but also in assessing appropriate
levels of competency. Useful guidelines and manuals dedicated to the critical
care physician are becoming available (De Backer et al. 2011; McLean and Huang,
2012).

Intensive Care Medicine and
Echocardiography

Echo has many advantages in the ICU with rapid application at the
bedside, using either transthoracic (TTE) or transoesophageal (TOE)
echocardiography for the purposes of cardiac diagnosis, haemodynamic
evaluation, haemodynamic monitoring, and assistance in therapeutic procedures.
Often the diagnostic information cannot be readily obtained by alternative
invasive techniques, including fixed and dynamic valvular dysfunction, left
ventricular diastolic dysfunction, the presence of segmental wall abnormalities
in reduced left ventricular contractile dysfunction, and pericardial tamponade.
Many of the underlying components contributing to circulatory status are
readily assessed when haemodynamic evaluation/monitoring is the primary focus
of a study (see Figure 1).

It is beyond the brief of this article to describe in detail the
considerable information an experienced operator can obtain from a single or
multiple studies; the benefits of critical care echo are well described
elsewhere (Repesse et al. 2013; De Backer et al. 2011).

Machine Selection, Acquisition and
Maintenance

A variety of ultrasound machines with cardiac capability are
available, and selection should be approached in a deliberate and pragmatic
manner. Often selection decisions are influenced by exposure to the same brand
in another setting such as central line insertion in the operating theatre,
persuasiveness of the sales representative, bias of other departments owning an
echo machine, and automatically updating that particular brand. Technological
advancements have created a wide range of available machines with varying
capabilities over a cost range from 10,000 to 200,000 Euros. The medium range
of ultrasound machines today, the size of a laptop computer, is markedly more
sophisticated than a large high-end machine available 20 years ago, yet today
costing one third of the larger one purchased at that time.

Selection criteria should be objective, with considerations of
proposed additional noncardiac ultrasound uses of machine, software content,
mobility, maintenance costs, upgrade ability, transoesophageal echocardiography
(TOE) capability, and, underlying all these criteria, the cost or rather value
for money. Only limited assistance is available in the literature, with
comparison of machines in specific considerations or for targeted software
applications (Royal College of Radiologists 2005; Wynd et al. 2009). One reason
for this void is that machines are in continual evolution and an evaluation is
outdated at the time of publication. Generic considerations to assist a
rational approach are given in Table 1. For those engaged in newer advanced
software applications like strain-rate and speckle tracking, an appreciation of
intersystem agreements is important (Nelson et al. 2012; Fine et al. 2012).

Image Acquisition and Archiving

Acquiring a proper set of sequential images, with cardiac cycle
timing provided by concurrent ECG monitoring should be standard practice. The
practice of waving a transducer hurriedly across the chest belongs to the amateurish
past. For both transthoracic echocardiography (TTE) and TOE a predetermined standard
set of views should be attempted, even though it is anticipated not all will
provide suitable images. Images from each view should be recorded.

Evolution from utilising echocardiography as a quick diagnostic
tool to a haemodynamic assessment/monitoring one necessitates image storage for
later review, post-processing, or comparison with subsequent studies. Since any
machine has limited internal storage, an external archiving system is an
important component to consider when developing an in-house critical care echo
service. Access to a system external to the ICU, such as a hospital clinical information
system, radiology or cardiology system, is preferable to setting up a stand-alone
system. It is less costly and also allows access to images elsewhere in the hospital.
However, this is not always possible and a stand-alone system is necessary. There
are two possible approaches – that of a proprietary system, using the same
supplier as the machine provider, or a ‘home grown’ variety. The latter is less
expensive and is not so difficult where local IT assistance is available, but
may not have the same post-processing ability as a proprietary system. If
multiple different machines are in use then a vendor neutral platform becomes
an important consideration (Strowig 2013) (see Figure 2). Reporting of studies
is essential. It improves the diagnostic and analytical skills of the operator,
delivers necessary information to the medical team caring for the patient, and
provides a succinct record. Archiving reports is also important, and some
systems store both images and reports.

Training

Dedicated enthusiasts have brought echocardiography from the
periphery of critical care practice to what can appropriately be regarded as an
essential tool in patient care. Introducing the practice into the ICU has by necessity
developed in an ad hoc manner, dependent upon local resources, physician
commitment, management support and, frequently, external political influences.
Training has generally been via the apprenticeship model, resulting in a
gradual increase of critical care physicians competent in the provision of around
the clock bedside echo assisted patient management. Over the past two decades,
training programmes to cope with the increasing demand have developed, the most
notable example being established in France. To fill the training gap within
the ICU setting, programmes initially came from a general ultrasound background
or were cardiology based with a critical care flavour. The recognition that
many aspects of echo application in the ICU setting differ substantially from
those of radiology or cardiology, namely the need to rapidly assess multiple
haemodynamic parameters, has led to a focus on developing specific CCE training
programmes (Mayo et al. 2009). This need is further accentuated by Intensive
Care training programmes around the world, making competency in basic echocardiography
a mandatory component in the overall training programme.

Once the necessity of training critical care physicians in echocardiography
was established, the question then arose as to what were acceptable levels of
competency. Gaining experience is a continuum from the moment a doctor first
places a transducer on the patient’s chest, to measuring strain-rate in the
right ventricular free wall. The next important step was international
cooperation in determining the components required for competency in basic
critical ultrasound, with a major emphasis on echocardiography. Representatives
from Intensive Care bodies in Europe, Asia- Pacific, North America and South
America met in Vienna in 2009, and a consensus paper was subsequently published
in 2011 (Expert Round Table on Ultrasound in the ICU, 2011). This recommended
that all trainee intensivists should be capable of performing a basic critical care
echocardiographic study. A smaller proportion of physicians will seek to
develop competency in advanced practice, with the emphasis moving from
diagnosis alone, to diagnosis and haemodynamic assessment using both TTE and
TOE. It is recognised that simulation techniques may enhance training,
especially in TOE (Shakil et al. 2012). Recommendations on what constitutes
advanced practice are now available in the literature (Narasimhan et al. 2014a;
Narasimhan et al. 2014b). Some countries such as France and Australia already have
training and credentialing programmes for critical care physician in advanced
practice. Although individual institutions or countries can set standards, there
is considerable benefit in developing international criteria. To achieve this
single objective, a gathering of expert representatives from multiple national
Intensive Care bodies met to debate and identify what constitutes advanced
competency in Critical Care Echocardiography. This consensus document will be
published in Intensive Care Medicine early in 2014 (Vieillard-Baron 2014). Such
documents do not necessarily prescribe what a particular institution or
national IC training body should do, but rather provide guidelines. This may have
more value in those ICUs where the Director is not au fait with
echocardiography.

Summary

Echocardiography is becoming commonplace in the ICU
setting, and this evolution brings with it responsibilities to provide a competent,
safe, and meaningful service to the patient. The simple approach of merely obtaining
an ultrasound machine and performing studies is no longer valid. It is necessary
to organise a service in a rational, sustainable, efficient way and ensure doctors
involved in performing the studies have demonstrated competency, either at
basic or advanced levels.

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